CN217002047U - Turbine bypass valve and turbocharger - Google Patents

Abstract

The present disclosure provides a turbine bypass valve and a turbocharger. The turbine bypass valve has a turbine housing in which a main flow passage and a bypass flow passage are integrated, a valve rotor whose rotation allows the bypass flow passage to selectively communicate with the main flow passage, and a cover plate whose axial movement is defined by the turbine housing and the cover plate, so that the turbine bypass valve maintains a stable operating state for a long time.

Description

Turbine bypass valve and turbocharger

Technical Field

The disclosure belongs to the technical field of turbochargers, and particularly relates to a turbine bypass valve and a turbocharger.

Background

This section is intended to provide a background or context to the embodiments of the disclosure recited in the claims. The description herein is not admitted to be prior art by inclusion in this section.

Turbines are well known devices for converting kinetic energy within a flowing gas into useful work. Known turbines convert the kinetic energy of the flowing gas into rotational kinetic energy of the turbine wheel of the turbine. The rotation of the turbine wheel may be transmitted by a suitable linkage to any device suitable for the useful work. Examples of such devices include an electrical generator (such that the turbine forms part of a power turbine) and a compressor (such that the turbine forms part of a turbocharger).

The turbine of the turbocharger receives exhaust gas from the internal combustion engine, thereby rotating the turbine wheel of the turbocharger to drive rotation of the compressor wheel. The compressor wheel draws in and pressurizes gas such that the pressure of the gas at the output of the compressor is increased compared to the gas at the inlet of the compressor. The output of the compressor of the turbocharger may be supplied to the inlet of an internal combustion engine of which the turbocharger forms a part.

In some applications of turbines, a turbine bypass valve may be required to cause exhaust gas produced by an engine to which the turbine is attached to bypass the turbine so that the exhaust gas flows to exhaust gas aftertreatment of the engine without passing through the turbine wheel.

Some turbine bypass valves known to the inventors are rotary valves. The rotary valve includes a housing defining a valve chamber at a junction of the inlet port, the outlet port, and the bypass port. The valve rotor is supported for rotation within the valve chamber. The valve rotor is rotatable about the valve axis between a first position in which the valve rotor allows airflow through the bypass port and a second position in which the valve rotor prevents airflow through the bypass port.

The housing of some rotary valves known to the inventors is formed by a portion of the turbine casing. In order to mount the valve rotor in the turbine casing, two holes need to be made in the turbine casing, one relatively large and one relatively small. The valve rotor is inserted into the valve chamber from the large bore and has one end pierced by the small bore, and the large bore is subsequently closed with a cover plate. The part of the valve rotor, which penetrates out of the small hole, is used for connecting with an actuating structure so as to drive the valve rotor to rotate by the actuating mechanism.

Axial displacement within the valve chamber of the valve rotor is unavoidable and needs to be stably limited to a minimum for proper operation of the turbine bypass valve.

SUMMERY OF THE UTILITY MODEL

The present disclosure provides a turbine bypass valve and a turbocharger.

The technical scheme adopted by the disclosure is as follows: a turbine bypass valve comprising: a turbine casing, a valve rotor and a cover plate;

the turbine casing includes a main flow passage including a front end flow passage defined by an intake flange and a volute tongue and a rear end flow passage defined by the volute tongue and an exhaust port of the main flow passage, and a bypass flow passage communicating with the main flow passage at the front end flow passage position and forming a valve chamber in which the valve rotor is provided rotatably along a rotation axis at a junction of the bypass flow passage and the front end flow passage;

the inlet flange is configured to receive a gas, the valve rotor blocks flow of the generator exhaust gas into the bypass flow passage and allows flow of the gas into the rear end flow passage when the valve rotor is rotated about the axis of rotation to a first position, the valve rotor allows flow of the gas into the bypass flow passage when the valve rotor is rotated about the axis of rotation to a second position, the bypass flow passage and the rear end flow passage both configured to discharge the gas into an exhaust gas treatment system;

the valve rotor is provided with a first end part, a middle part and a second end part which are sequentially arranged along one extending direction of the rotation axis, the central axis of a smallest surrounding cylinder of the first end part, the middle part and the second end part is the rotation axis, the turbine shell is provided with a first through hole and a second through hole which are opposite to each other at the position opposite to the front end flow passage, the first end part of the valve rotor penetrates out of the first through hole to be connected with an actuating mechanism which drives the valve rotor to rotate around the rotation axis, and the cover plate covers the second through hole and forms a containing groove which contains the second end part of the valve rotor;

a minimum surrounding cylinder of a middle portion of the valve rotor has a diameter larger than diameters of minimum surrounding cylinders of the first and second end portions, the first through hole is a stepped hole having an opening size at an inner surface of the turbine casing larger than an opening size of the first through hole at an outer surface of the turbine casing, and a stepped surface of the first through hole is opposed to a first end surface of the middle portion to define a maximum distance of movement of the valve rotor in a direction from the second end portion toward the first end portion;

an outer region of the receiving groove of the cover plate is opposite to a second end face of the intermediate portion to define a maximum distance that the valve rotor moves in a direction directed from the first end portion to the second end portion.

The technical scheme adopted by the disclosure is as follows: a turbocharger comprising the turbine bypass valve as described above.

Compared with the prior art, the beneficial effect of this disclosure is: the valve rotor is restrained against movement in both directions of its axis of rotation by a turbine housing and a cover plate which are themselves sufficiently structurally stable to allow axial movement of the valve rotor to be stably restrained to a minimum.

Drawings

FIG. 1 is a cross-sectional view of a turbine bypass valve according to an embodiment of the present disclosure.

FIG. 2 is a perspective cut-away view of a turbine bypass valve according to an embodiment of the present disclosure.

FIG. 3 is a cross-sectional view of a turbine bypass valve according to an embodiment of the present disclosure.

FIG. 4 is a cross-sectional view of a turbine bypass valve according to an embodiment of the present disclosure.

Wherein, 1, turbine casing; 10. an air inlet flange; 11. a front end runner; 12. a rear end flow passage; 13. a bypass flow channel; 14. a vortex tongue; 15. an exhaust port; 3a, a first front end runner; 3b, a second front end runner; 4. a valve rotor; 41. A first end portion; 42. an intermediate portion; 43. a second end portion; 5. a rocker arm; 6a, a first bushing; 6b, a second bushing; 7. a cover plate; 8a, 8b, 8c, 8d, 8e, 8f, sealing ring.

Detailed Description

The present disclosure is further described below with reference to the embodiments shown in the drawings.

Referring to fig. 1-4, an embodiment of the present disclosure provides a turbine bypass valve comprising: a turbine casing 1, a valve rotor 4 and a cover plate 7.

The turbine housing 1 includes a main flow passage including a front end flow passage 11 defined by an intake flange 10 and a scroll tongue 14 and a rear end flow passage 12 defined by the scroll tongue 14 and an exhaust port 15 of the main flow passage, and a bypass flow passage 13 communicating with the main flow passage at the position of the front end flow passage 11 and forming a valve chamber in which the valve rotor 4 is provided rotatably along a rotation axis at a junction of the bypass flow passage 13 and the front end flow passage 11.

With reference to fig. 1, an inlet flange 10 may be used to secure the turbine casing 1 to the end of the engine exhaust manifold. The inlet flange 10 forms the inlet of the main flow channel of the turbine casing 1. Exhaust gas from the engine flows into the rear end flow passage 12 in the main flow passage to rotate a turbine wheel (not shown), and the exhaust gas finally flows from the exhaust port 15 of the main flow passage into an exhaust gas treatment system (not shown). In the exhaust gas treatment system, harmful substances in the exhaust gas are reduced, and the exhaust gas is cooled and discharged into the atmosphere.

The inlet flange 10 is adapted to receive gas, the valve rotor 4 blocking flow of engine exhaust gas into the bypass flow passage 13 and allowing flow of gas into the rear end flow passage 12 when the valve rotor 4 is rotated about the axis of rotation to a first position, the valve rotor 4 allowing flow of gas into the bypass flow passage 13 when the valve rotor 4 is rotated about the axis of rotation to a second position, the bypass flow passage 13 and the rear end flow passage 12 both being adapted to discharge gas into the exhaust gas treatment system.

According to the current view of fig. 1, the axis of rotation of the valve rotor 4 is perpendicular to the paper. In the present state of fig. 1, part of the gas flowing from the inlet flange 10 into the front end flow channel 11 flows into the bypass flow channel 13, thereby avoiding an excessive turbine wheel speed.

According to the current view of fig. 1, after the valve rotor 4 rotates counterclockwise by a certain angle, the bypass flow channel 13 is disconnected from the front end flow channel 11. In this state, all of the gas flowing into the turbine housing 1 from the intake flange 10 is discharged into the rear-end flow passage 12.

The exhaust gas flowing out of the bypass flow path 13 and the rear flow path 12 is finally discharged into the exhaust gas treatment system. The end of the bypass flow passage 13 may communicate with the rear end flow passage 12 in the turbine casing 1 so that the exhaust gas flows out only from the rear end flow passage 12. The exhaust gas may flow out of the bypass flow path 13, join the exhaust gas flowing out of the rear end flow path 12 outside the turbine casing 1, and flow into the exhaust gas treatment system.

In some embodiments, as shown in fig. 2 to 4, the front end flow passage 11 is divided into a first front end flow passage 3a and a second front end flow passage 3b, and at least a front section of the bypass flow passage is divided into a first bypass flow passage and a second bypass flow passage independent of each other. The exhaust gas flowing into the turbine bypass valve from both the first front-end flow passage 3a and the second front-end flow passage 3b flows into the single rear-end flow passage 12. The exhaust gas flowing through the turbine bypass valve from the first front-end flow passage 3a may also partially or entirely flow into the first bypass flow passage, and the exhaust gas flowing through the turbine bypass valve from the second front-end flow passage 3b may also partially or entirely flow into the second bypass flow passage.

In some embodiments, the front end flow channel 11 is a single flow channel or a dual flow channel.

In other embodiments, the front end flow channel 11 and the bypass flow channel 13 are both a single flow channel.

The valve rotor 4 is provided with a first end part 41, a middle part 42 and a second end part 43 which are sequentially arranged along one extending direction of the rotation axis, the central axes of the minimum surrounding cylinders of the first end part 41, the middle part 42 and the second end part 43 are all the rotation axis, the turbine shell 1 is provided with a first through hole and a second through hole which are opposite to each other at the position opposite to the front end flow passage 11, the first end part 41 of the valve rotor 4 penetrates out of the first through hole to be connected with an actuating mechanism which drives the valve rotor 4 to rotate around the rotation axis, and the cover plate 7 covers the second through hole and forms a containing groove which contains the second end part 43 of the valve rotor 4.

The actuating mechanism comprises a rocker arm 5, the first end portion 41 being rotated about an axis of rotation by the rocker arm 5. According to the present viewing angle of fig. 3 and 4, the axis of rotation is an imaginary line in the vertical direction.

In the present view of fig. 3 and 4, the first via is located above the second via.

The second through hole is slightly larger in size than the intermediate portion 42, so that the valve rotor 4 can be inserted into the valve chamber from the second through hole when assembling the turbine bypass valve.

Precisely, the orthographic projection of the valve rotor 4 on a plane perpendicular to the axis of rotation should be within the orthographic projection of the second through hole on this plane.

The intermediate portion 42 of the valve rotor 4 is generally designed in a cylindrical shape with a missing area, which facilitates the close contact between the valve rotor 4 and the inner surface of the valve chamber, and also enables the opening and closing of the inlet port of the bypass flow passage 13 by the intermediate portion 42 of the valve rotor 4.

The diameter of the smallest surrounding cylinder of the intermediate portion 42 of the valve rotor 4 is larger than the diameters of the smallest surrounding cylinders of the first and second end portions 41 and 43, the first through hole is a stepped hole whose opening size at the inner surface of the turbine casing 1 is larger than that at the outer side of the turbine casing 1, and one stepped surface of the first through hole is opposed to the first end surface of the intermediate portion 42 to define the maximum distance that the valve rotor 4 moves in the direction from the second end portion 43 toward the first end portion 41.

The outer region of the receiving groove of the cover plate 7 is opposed to the second end face of the intermediate portion 42 to define the maximum distance that the valve rotor 4 moves in the direction directed from the first end portion 41 to the second end portion 43.

According to the present view of fig. 3 and 4, when the upper surface of the upper end portion of the middle portion 42 of the valve rotor 4 is moved upward to be in contact with the lower surface of one step surface of the first through hole of the turbine casing 1, there is still a certain gap in the up-down direction between the remaining area of the middle portion 42 of the valve rotor 4 not in contact with the lower surface and the first end portion 41 and the remaining components of the periphery.

According to the present view of fig. 3 and 4, when the lower surface of the lower end portion of the middle portion 42 of the valve rotor 4 moves downward to contact the upper surface of the area outside the receiving groove of the cover plate 7, there is still a certain gap in the up-down direction between the area of the middle portion 42 of the valve rotor 4 not contacting the cover plate 7 and the second end portion 43 and the rest of the periphery.

The valve rotor 4 is restrained by the turbine casing 1 and the cover plate 7 from moving in both directions of its rotation axis, and the structural stability of the turbine casing 1 and the cover plate 7 itself is sufficiently strong so that the axial moving distance of the valve rotor 4 is stably restricted to the minimum movable section. Generally the axial movement distance of the valve rotor 4 should be limited to the range of 0.5 mm.

Referring to fig. 3, the turbine bypass valve further includes a first seal ring 8a, both inner and outer circumferential surfaces of the first seal ring 8a are cylindrical side surfaces, the inner and outer circumferential surfaces of the first seal ring 8a are coaxial with a smallest surrounding cylinder of the intermediate portion 42 of the valve rotor 4, and the first seal ring 8a further has two first side planes connecting the inner and outer circumferential surfaces of the first seal ring, both of which are perpendicular to the rotation axis.

The peripheral area of the first end surface of the intermediate portion 42 also forms a first annular notch, and the first annular notch forms a first truncated cone on the first end surface of the intermediate portion 42.

The outer peripheral surface of the first sealing ring 8a is in interference fit with one step surface of the first through hole, the inner peripheral surface of the first sealing ring 8a is in clearance fit with the side surface of the first circular table, and two first side planes of the first sealing ring 8a are in clearance fit with the other step surface of the first through hole and the entity of the middle part 42, which is positioned outside the first circular table.

A stepped bore typically has an inner surface that is parallel or approximately planar with the opening of the stepped bore, and an inner surface that is perpendicular or approximately perpendicular to the opening of the stepped bore, both of which are referred to as step faces in this disclosure.

According to the current view of fig. 3, the entity of the middle portion located outside the first circular truncated cone is also the entity below the first annular notch.

Referring to fig. 3, the turbine bypass valve further includes a second seal ring 8c, the inner circumferential surface and the outer circumferential surface of the second seal ring 8c are both cylindrical side surfaces, the inner circumferential surface and the outer circumferential surface of the second seal ring 8c are coaxial with the smallest surrounding cylinder of the middle portion 42 of the valve rotor 4, the second seal ring 8c further has two second side planes connecting the inner circumferential surface and the outer circumferential surface of the second seal ring 8c, the two second side planes are perpendicular to the rotation axis, the outer circumferential area of the second end face of the middle portion 42 further forms a second annular gap, the second annular gap forms a second circular truncated cone on the second end face of the middle portion 42, the cover plate 7 has an annular boss for receiving the middle portion 42, the outer circumferential surface of the second seal ring 8c is in interference fit with an inner annular boss, the inner circumferential surface of the second seal ring 8c is in clearance fit with a side surface of the second circular truncated cone, and the two second side planes of the second seal ring 8c are respectively in interference fit with an entity of the middle portion 42 and the cover plate 7 located outside the second circular truncated cone Is in solid clearance fit inside the annular boss.

In the present view according to fig. 3, the entity of the intermediate portion 42 located on the outside of the second circular truncated cone is the entity above the second annular gap.

Since fig. 3 shows a two-flow turbine bypass valve, a sealing ring 8b is also provided at the interface of the two flow paths.

When assembling the turbine bypass valve, the seal ring 8a is first installed in the valve chamber, the valve rotor 4 is then installed in the valve chamber together with the seal ring 8b, and finally the seal ring 8c is installed in the valve chamber. Although there are more mounting steps, the difficulty of each mounting step is relatively low.

Referring to fig. 4, the turbine bypass valve further includes a third seal ring 8d, an inner circumferential surface and an outer circumferential surface of the third seal ring 8d are both cylindrical side surfaces, the inner circumferential surface and the outer circumferential surface of the third seal ring 8d are coaxial with the smallest surrounding cylinder of the middle portion 42 of the valve rotor 4, the third seal ring 8d further has two third side planes connecting the inner circumferential surface and the outer circumferential surface of the third seal ring 8d, a first annular groove is provided on a section of the outer circumferential surface of the middle portion 42 of the valve rotor 4 near the first end portion 41, a surface of the turbine casing 1 opposite to the first annular groove is a step surface of the first through hole, the outer circumferential surface of the third seal ring 8d is in interference fit with the step surface of the first through hole, the inner circumferential surface of the third seal ring 8d is in clearance fit with a bottom surface of the first annular groove, and the two third side planes of the third seal ring 8d are in clearance fit with one side surface of the second annular groove.

Referring to fig. 4, the turbine bypass valve further includes a fourth sealing ring 8f, the inner circumferential surface and the outer circumferential surface of the fourth sealing ring 8f are both cylindrical side surfaces, the inner circumferential surface and the outer circumferential surface of the fourth sealing ring 8f are coaxial with the smallest surrounding cylinder of the middle portion 42 of the valve rotor 4, the fourth sealing ring 8f further has two fourth side flat surfaces connecting the inner circumferential surface and the outer circumferential surface of the fourth sealing ring 8f, a second annular groove is provided on a section of the outer circumferential surface of the middle portion 42 of the valve rotor 4 near the second end portion 43, a surface of the turbine casing 1 opposite to the second annular groove is a cylindrical side surface coaxial with the rotation axis, the outer circumferential surface of the fourth sealing ring 8f is in interference fit with the turbine casing 1, the inner circumferential surface of the fourth sealing ring 8f is in clearance fit with the bottom surface of the second annular groove, and the two fourth side flat surfaces of the fourth sealing ring 8f are in clearance fit with one side surface of the second annular groove, respectively.

Since fig. 4 shows a double-flow turbine bypass valve, a sealing ring 8e is also provided at the interface of the two flow paths.

In assembling the turbine bypass valve, the seal rings 8d, 8e and 8f are first fitted over the intermediate portion 42, and then these 3 seal rings are inserted into the valve chamber together with the valve rotor 4.

The turbine bypass valve shown in fig. 3 is, in contrast, simpler to install, while the turbine bypass valve shown in fig. 4 is better sealed.

In some embodiments, the turbine bypass valve further comprises a first bushing 6a surrounding the first end portion 41 and located inside the first through hole, a second bushing 6b surrounding the second end portion 43 and located inside the second through hole, the first bushing 6a being axially spaced from the intermediate portion 42, and the second bushing 6b being axially spaced from the intermediate portion 42.

To increase the sealing performance of the turbine bypass valve, a cylindrical first bushing 6a is fitted around the outside of the first end 41 of the valve rotor 4. The first bush 6a is interference-fitted with the inner surface of the first through hole of the turbine casing 1. The axial distance of the first bushing 6a from the central part 42 of the valve rotor 4 can be provided slightly larger. The second cylindrical bushing 6b is fitted around the second end 43 of the valve rotor 4. The second bush 6b is in interference fit with the inner side surface of the receiving groove of the cover plate 7. The axial distance of the second bush 6b from the cover plate 7 can be set slightly larger.

The above turbine casing 1, the valve rotor 4, the first bushing 5a, the second bushing 6b, the cover plate 7, and the seal rings 8a to 8f may be made of suitable metal materials. The hardness of the sealing rings 8a to 8f should be relatively greater than that of the remaining components.

Based on the same inventive concept, embodiments of the present disclosure also provide a turbocharger including the aforementioned turbine bypass valve. The present disclosure does not limit the design of the remaining components of the turbocharger. For example, the turbocharger also includes a turbine wheel mounted in the rear end flow passage 12 and a shaft supporting the turbine wheel for rotation. The turbine wheel and the turbine bypass valve form a turbine which integrates the bypass valve and the bypass flow channel 13. Of course, the turbocharger should also include a compressor, with the shaft of the turbine turning the shaft of the compressor. As another example, an intermediate casing is typically provided between the turbine and compressor casings.

The embodiments in the present disclosure are described in a progressive manner, and the same and similar parts among the embodiments can be referred to each other, and each embodiment focuses on differences from other embodiments.

The scope of the present disclosure is not limited to the above-described embodiments, and it is apparent that various modifications and variations can be made to the present disclosure by those skilled in the art without departing from the scope and spirit of the present disclosure. It is intended that the present disclosure also encompass such modifications and variations as fall within the scope of the claims and their equivalents.

Claims (8)

1. A turbine bypass valve, comprising: a turbine casing (1), a valve rotor (4) and a cover plate (7);

the turbine casing (1) includes a main flow passage including a front end flow passage (11) defined by an intake flange (10) and a volute tongue (14) and a rear end flow passage (12) defined by the volute tongue (14) and an exhaust port (15) of the main flow passage, and a bypass flow passage (13), the bypass flow passage (13) communicating with the main flow passage at the position of the front end flow passage (11) and forming a valve chamber in which the bypass flow passage (13) is connected to the front end flow passage (11), the valve rotor (4) being provided in such a manner as to be rotatable along a rotation axis;

the intake flange (10) is configured to receive gas, the valve rotor (4) blocks engine exhaust gas from flowing into the bypass flow channel (13) and allows the gas to flow into the rear end flow channel (12) when the valve rotor (4) is rotated about the axis of rotation to a first position, the valve rotor (4) allows the gas to flow into the bypass flow channel (13) when the valve rotor (4) is rotated about the axis of rotation to a second position, the bypass flow channel (13) and the rear end flow channel (12) both configured to discharge the gas into an exhaust gas treatment system;

the valve rotor (4) is provided with a first end part (41), a middle part (42) and a second end part (43) which are sequentially arranged along one extending direction of the rotation axis, the central axes of the minimum enclosing cylinders of the first end part (41), the middle part (42) and the second end part (43) are all the rotation axis, the turbine casing (1) is provided with a first through hole and a second through hole which are opposite to each other at the position opposite to the front end runner (11), the first end part (41) of the valve rotor (4) penetrates through the first through hole to be connected with an actuating mechanism which drives the valve rotor (4) to rotate around the rotation axis, and the cover plate (7) covers the second through hole and forms a containing groove which contains the second end part (43) of the valve rotor (4);

a diameter of a smallest surrounding cylinder of an intermediate portion (42) of the valve rotor (4) is larger than diameters of smallest surrounding cylinders of the first end portion (41) and the second end portion (43), the first through hole is a stepped hole having an opening size at an inner surface of the turbine casing (1) larger than an opening size at an outer surface of the turbine casing (1), and a stepped surface of the first through hole is opposed to a first end surface of the intermediate portion (42) to define a maximum distance of movement of the valve rotor (4) in a direction from the second end portion (43) toward the first end portion (41);

an outer region of the receiving groove of the cover plate (7) is opposed to a second end face of the intermediate portion (42) to define a maximum distance of movement of the valve rotor (4) in a direction directed from the first end portion (41) to the second end portion (43).

2. The turbine bypass valve according to claim 1, characterized by further comprising a first seal ring (8a), both inner and outer peripheral surfaces of which are cylindrical side surfaces, the inner and outer peripheral surfaces of the first seal ring (8a) being coaxial with a smallest surrounding cylinder of the intermediate portion (42) of the valve rotor (4), the first seal ring (8a) further having two first side planes connecting the inner and outer peripheral surfaces of the first seal ring (8a), both of which are perpendicular to the rotation axis, a peripheral region of the first end surface of the intermediate portion (42) further forming a first annular gap that forms a first circular truncated cone on the first end surface of the intermediate portion (42), the outer peripheral surface of the first seal ring (8a) being interference-fitted with one step surface of the first through hole, the inner circumferential surface of the first sealing ring (8a) is in clearance fit with the side surface of the first circular truncated cone, and two first side planes of the first sealing ring (8a) are in clearance fit with the other step surface of the first through hole and the entity of the middle part (42) which is positioned on the outer side of the first circular truncated cone respectively.

3. The turbine bypass valve according to claim 1, characterized by further comprising a second seal ring (8c), the inner and outer peripheral surfaces of which are both cylindrical side surfaces, the inner and outer peripheral surfaces of the second seal ring (8c) being coaxial with the smallest surrounding cylinder of the intermediate portion (42) of the valve rotor (4), the second seal ring (8c) further having two second side planes connecting the inner and outer peripheral surfaces of the second seal ring (8c), both of which are perpendicular to the rotation axis, the peripheral area of the second end face of the intermediate portion (42) further forming a second annular indentation that forms a second circular truncated cone on the second end face of the intermediate portion (42), the cover plate (7) having an annular boss that receives the intermediate portion (42), the outer peripheral surface of the second sealing ring (8c) is in interference fit with the inner annular surface of the annular boss, the inner peripheral surface of the second sealing ring (8c) is in clearance fit with the side surface of the second circular truncated cone, and two second side planes of the second sealing ring (8c) are in clearance fit with an entity of the middle part (42) located on the outer side of the second circular truncated cone and an entity of the cover plate (7) located on the inner side of the annular boss respectively.

4. The turbine bypass valve according to claim 1, characterized by further comprising a third seal ring (8d), wherein the inner and outer peripheral surfaces of the third seal ring (8d) are both cylindrical side surfaces, the inner and outer peripheral surfaces of the third seal ring (8d) are coaxial with the smallest surrounding cylinder of the middle portion (42) of the valve rotor (4), the third seal ring (8d) further has two third side planes connecting the inner and outer peripheral surfaces of the third seal ring (8d), a first annular groove is provided on a section of the outer peripheral surface of the middle portion (42) of the valve rotor (4) near the first end portion (41), a surface of the turbine housing (1) opposite to the first annular groove is a step surface of the first through hole, and the outer peripheral surface of the third seal ring (8d) is in interference fit with the step surface of the first through hole, the inner circumferential surface of the third sealing ring (8d) is in clearance fit with the bottom surface of the first annular groove, and two third side planes of the third sealing ring (8d) are in clearance fit with one side surface of the first annular groove respectively.

5. The turbine bypass valve according to claim 1, characterized by further comprising a fourth seal ring (8f), wherein the inner and outer circumferential surfaces of the fourth seal ring (8f) are both cylindrical side surfaces, the inner and outer circumferential surfaces of the fourth seal ring (8f) are coaxial with the smallest surrounding cylinder of the intermediate portion (42) of the valve rotor (4), the fourth seal ring (8f) further has two fourth side planes connecting the inner and outer circumferential surfaces of the fourth seal ring (8f), a section of the outer circumferential surface of the intermediate portion (42) of the valve rotor (4) near the second end portion (43) is provided with a second annular groove, the surface of the turbine housing (1) opposite to the second annular groove is a cylindrical side surface coaxial with the rotation axis, and the outer circumferential surface of the fourth seal ring (8f) is in interference fit with the turbine housing (1), the inner circumferential surface of the fourth sealing ring (8f) is in clearance fit with the bottom surface of the second annular groove, and two fourth side planes of the fourth sealing ring (8f) are in clearance fit with one side surface of the second annular groove respectively.

6. A turbine bypass valve according to claim 1, characterized in that the front end flow channel (11) is a single or double flow channel.

7. The turbine bypass valve according to claim 1, further comprising a first bushing (6a) surrounding the first end portion (41) and located inside the first through hole, a second bushing (6b) surrounding the second end portion (43) and located inside the second through hole, the first bushing (6a) being axially spaced from the intermediate portion (42), the second bushing (6b) being axially spaced from the intermediate portion (42).

8. A turbocharger comprising a turbine bypass valve according to any one of claims 1 to 7.

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